/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/

new Promise((resolve) => {
  let a = "hello";
  setTimeout(() => resolve(a), 10);
})
  .then((a) => {
    return new Promise((resolve) => {
      let b = "lagou";
      setTimeout(() => resolve(a + b), 10);
    });
  })
  .then((res) => {
    let c = "I ♥ U";
    setTimeout(() => {
      console.log(res + c);
    }, 10);
  });
